Projectile Penetration in Soil and Rock: Analysis for Non-Normal Impact

Abstract

An empirical rigid-projectile analysis has been developed for non- normal impact and penetration into soil and rock. The soil penetration analysis uses Young's S-number as the penetrability index. The rock penetration analysis calculates resistance-to-penetration using density, strength, and Rock Quality Designation. Expressions for compressive normal stress are integrated numerically over the projectile surface using the differential area force law in the PENCO2D computer code. The analysis includes free-surface and wake separation-reattachment effects. The PENCO2D code is used to make comparison calculations for Sandia/DNA reverse ballistic tests and several full-scale tests conducted by Sandia Laboratories. A parameter study shows effects of soil penetrability, impact velocity, initial attack and obliquity angles, and projectile geometry on underground trajectories.